Hi - this will be my third cycle of using the digital monitor. It's so easy and clear to use. I used the cheapy sticks before but wasn't getting a really dark line when I ov-d so nearly missed my peak time. There's no uncertainty with the monitor. You know exactly when your peak fertility time is and it tests your oestrogen levels as well. I've found it a loss less stressful than the POAS. The sticks you buy for it are more expensive but once you've used it and worked out roughly when you ovulate, you can cut down on the amount you use. The monitor asks me to start using them on day 6 but I don't bother until day 8 or 9. If you can afford it, get one!